I had this issue with my old DICE unit as well. The version I had was pre-iphone and it had this noise. I did what danq989 did and just turned off the scrolling.

I'm fairly certain that the noise is from crosstalk within the module itself. Moreover, the wire bundle running from the module to the trunk (not sure how it is done now) is likely contributing to the problem as well. If I am correct, it appears that there is a DAC in the module since everything coming off the bottom should be a digital signal. That means that an unshielded analog audio signal is running in the same bundle as the digital format track information.

Then again, there are so many points along the line that could be causing this, the only way to troubleshoot is to try everything and rule them out one by one. Good luck!